The obituary of moderates in Congress has been written a million times: Middle-of-the-road Republicans are almost extinct; Blue Dogs are losing in droves; the institution is stuck in ideological gridlock.

And that all appears true. Enter the New Democrat Coalition, a group of House Democrats trying to redefine what it means to be a moderate in a hyper-polarized environment. It’s someone, based on the group’s profile, who can embrace cap and trade and the health care overhaul and at the same time call for more free trade and corporate tax rate cuts.

Now, the so-called New Dems — whose politics range roughly from far left to slightly left of center — are gunning for a host of battleground seats in suburban America that could tip the House back to their party this fall.

“When we win back the House, it is going to be because of the linchpin, which is the New Democrat Coalition,” said the group’s chairman, New York Rep. Joe Crowley. “That is going to be the focus of the appeal — not only to Democrats but to independent voters.”

The New Dems’ formula for survival in an increasingly polarized Capitol Hill: tack left on social issues but veer toward the center on business- and economic-oriented policies that could appeal to independent and moderate voters.

But defining the group’s ideological moorings is a tricky exercise.

Though the New Dems proudly tout their centrist label, six of its 42 members also belong to the liberal Congressional Progressive Caucus — Reps. Karen Bass and Laura Richardson of California, Andre Carson of Indiana, Rush Holt of New Jersey, Jim Moran of Virginia and Jared Polis of Colorado.

And all but three of current New Dems voted for the health care law in 2010. By contrast, nearly half of the more conservative Blue Dog Coalition’s current 25 members rejected the sweeping overhaul and distinguished themselves from the broader Democratic Party. A similar dynamic played out with the cap-and-trade vote in June 2009, when all but three New Dems backed the climate bill while 10 of the current Blue Dogs opposed it.

That’s not to say New Dems haven’t bucked their party on occasion. They enthusiastically supported the free-trade agreements last fall, although a vast majority of House Democrats opposed the deals with Panama, Colombia and South Korea. The group also withheld support for their party’s financial reform bill in 2010 until sections were rewritten to make it more palatable to them.

They also want to make comprehensive tax reform a marquee issue — outlining in a policy paper their broad objectives for simplifying the Tax Code, particularly lowering the marginal corporate tax rate.

“Obviously, we’re going to have a very diverse national party,” said Rep. Ron Kind (D-Wis.), a vice chairman for the New Dems. “But I also feel that the New Dems are providing a path forward to where the American people are and what they would like to see us working on.”

“They’re nonideological in that they have Blue Dogs and progressives, as well as members who aren’t in any of those other caucuses,” added Polis. “I think it runs the gamut [from] left to middle to right.”

Still, the group’s diverse ideological makeup invites criticism that New Dems are more interested in branding themselves as moderates among voters than actually legislating like moderates.

Former Rep. Charlie Stenholm (D-Texas), a centrist who served for 26 years on Capitol Hill until 2005, said the coalition’s support for cap and trade and the health care law weren’t exactly middle-of-the-road positions. Those policies, he argued, have damaged the party by casting it too far left.

“I think the New Democrats are going to be the ones that ultimately pull [us] back to the majority, but they’ve got a little pull to go,” said Stenholm, who was both a Blue Dog and a New Dem during his tenure. “If you pull to the left, you do not attract the middle.”

And Republicans, of course, aren’t convinced the New Dems’ brand of politics is a winning sell.

“This is the most pathetic spinoff since ‘Baywatch Nights,’” said National Republican Congressional Committee spokesman Paul Lindsay. “If Laura Richardson and Jim Moran are considered ‘moderate’ these days, I’d hate to see who they consider liberal.”

But New Dems say their political profile will be key in several competitive House races this fall, and several of the group’s top endorsements are in races that the Democratic Congressional Campaign Committee has pinpointed as prime pickup opportunities this November.

Among them are Ami Bera of California, Brad Schneider of Illinois, Denny Heck of Washington state, Joaquin Castro of Texas and Florida candidates Val Demings, Keith Fitzgerald and Pat Murphy. Former Reps. Bill Foster of Illinois and Dan Maffei of New York are also backed by the New Dems.

“I think there is a rising interest in the message of groups like the New Dems who are saying, ‘We need to stop the partisan bickering, put the differences aside and find that common ground,” said Schneider, a businessman who in March fended off a primary challenge from Ilya Sheyman — a candidate backed by national progressives.

The New Dems’ political arm has endorsed 20 current candidates and has raised $1.4 million this election cycle, according to the Center for Responsive Politics. The New Dems also boast of their ties to the DCCC, where three of the four national chair positions are held by New Dems. They include Crowley, the national finance chairman; Pennsylvania Rep. Allyson Schwartz, the national chairwoman for recruiting and candidate services; and Puerto Rico Del. Pedro Pierluisi (D-Puerto Rico), the national chairman for community mobilization.

DCCC Chairman Steve Israel of New York is a former New Dem member, and a handful of other New Dems have taken key roles at the DCCC.

The New Dems’ political efforts come at a time when the political center in Congress is getting pummeled. The 2010 midterms shredded the Blue Dog Coalition’s ranks, and with a handful of its 25 members retiring from the House and many more politically endangered this fall, its numbers could dwindle even further.

The April 24 Pennsylvania primaries knocked out two more of its card-carrying members: Reps. Jason Altmire, who had been drawn into the same district as Rep. Mark Critz, and Rep. Tim Holden, who was defeated by a liberal challenger in a dramatically redrawn seat.

“It’s not that the moderates are dying,” said Rep. John Barrow (D-Ga.), a Blue Dog and New Dem who also faces a tough reelection. “It’s that the districts are drawn in such a fashion to elect only extremists.”

New Dems also face political challenges of their own. Several of their members are prime targets for the NRCC, including Reps. Lois Capps of California , Russ Carnahan of Missouri and Bill Owens of New York.

The group has also lost primaries in which its members have intervened, such as in Maryland’s 6th District, where the New Dem-endorsed Rob Garagiola lost to John Delaney. Altmire, who lost in Pennsylvania, is also a New Dem and serves as chairman of the group’s political action committee.

While Blue Dogs primarily come from rural and Southern United States, the New Dems hail from suburban and exurban areas — which, Democrats believe, will be the battleground in House races this fall. And so while redistricting has dramatically weakened the Blue Dogs’ prospects, New Dems say redistricting actually has helped because their geographical strengths are in areas where it was more difficult to distort district lines, Crowley said.

“The success of the Democratic Party in the fall elections, I think, squarely is linked to the success of the New Democrat Coalition,” Crowley said. “Overall, the absence of a similar entity of the Republican Party is what I think is going to be problematic for them in the future.”